To meet the demand for wireless data traffic, which has increased since deployment of 4th-generation (4G) communication systems, efforts have been made to develop an improved 5th-generation (5G) or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a ‘beyond 4G network’ or a ‘post long-term evolution (LTE) system’.
It is considered that the 5G communication system will be implemented in millimeter wave (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To reduce propagation loss of radio waves and increase a transmission distance, a beam forming technique, a massive multiple-input multiple-output (MIMO) technique, a full dimensional MIMO (FD-MIMO) technique, an array antenna technique, an analog beam forming technique, and a large scale antenna technique are discussed in 5G communication systems.
In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, a device-to-device (D2D) communication, a wireless backhaul, a moving network, a cooperative communication, coordinated multi-points (CoMP), reception-end interference cancellation, and the like.
In the 5G system, a hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) modulation (FQAM) and a sliding window superposition coding (SWSC) as an advanced coding modulation (ACM) scheme, and a filter bank multi carrier (FBMC) scheme, a non-orthogonal multiple access (NOMA) scheme, and a sparse code multiple access (SCMA) scheme as an advanced access technology have been developed.
Meanwhile, in a public safety (PS) environment where a disaster such as an earthquake, a fire, and/or the like occurs, a specific base station (BS) may not normally operate, so a communication for a specific user equipment (UE) which exists within a communication coverage of the BS may be impossible. So, a relay scheme may be used, and the relay scheme uses a UE which exists within a communication coverage of another BS which normally operates, not the BS which may not normally operate.
The relay scheme is based on a D2D communication scheme. The specific UE for which the communication is impossible may transmit data to a relay UE providing a relay service according to a D2D communication scheme. After receiving the data transmitted by the specific UE, the relay UE may transmit the received data to a BS according to a cellular communication scheme.
If the number of remote UEs transmitting data using a relay UE increases, connections may converge on a specific relay UE. In this case, the relay UE on which the connections converge may not provide a normal service due to relay overload, so service delay may occur due to the relay overload.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.